One thing I've not spotted earlier in this thread . . IMO many Irish tunes work well SLOWER than is usual . . it's often a good experiment ("The Butterfly" is a good example of a tune whose "feel" is quite different at different speeds). While ANY tune can be wrecked by trying to play it too fast.

Sam - yes, you enjoy the manicly fast, but you have the skill and musicianship to keep it MUSICAL even at that speed . . there's too many for whom that can't be said (which is why we avoid Irish sessions in these parts; the musical enjoyment they offer is about zero).

And remember - a session is a social thing; playing a tune you know well at a breakneck speed can be downright antisocial, especially if it's on the difficult side.

G.